It is important to eat your greens and work out!
So you made a dangerous world filled with creatures and a threat around every corner. How will you enforce it? That's very easy; Health. You can easily give a specific amount of health to all the players roaming your world.
Go to Room -> Settings -> Health then enter the amount you like the players in your world to have. You can give them 10HP if you want them to suffer, or you can make them omnipotent by giving them something like 999999999999999HP
Giving 250HP to players